水稻条斑病菌III型效应子XopN致病机理研究

Bacterial leaf streak (BLS), caused by gram-negative bacterium Xanthomonas oryzae pv.oryzicola (Xoc), is one of the most serious diseases in the south of China. Due to limited knowledge about the molecular basis of Xoc pathogenicity and host defence mechanisms involved, so far there is no effective and environmental friendly methods to control the disease. In recent years, identification and functional study of type III effectors has become a hotspot in the field of plant-pathogen interaction. We previously found that type III effector gene XopN，which is highly conserved in genus Xanthomonas , is required for full virulence of Xoc. Results of our previous work also indicated that this effector most likely inhibited the host innate immune system and caused the host plant susceptible. This study will use molecular biology 、functional genomics technology 、TALEN or CRISPR/Cas9 system to identify host targets of XopN and reveal the pathogenic mechanism underlying the interactions between XopN and host plants. Our study will give insight into the mechanisms of the pathogenesis of Xoc, expand our knowledge on plant immunity, help us mining functional genes for crop genetic improvement and provides the theoretical basis for the development of new and effective BLS control strategies.

水稻条斑病（Bacterial leaf streak，BLS)是我国南方水稻生产中最严重的细菌性病害之一，病原为稻黄单胞菌栖稻致病变种（Xanthomonas oryzae pv.oryzicola，Xoc），由于对Xoc致病机理知之不多至今仍未能有效防控该病害。近年来植物病原细菌III型效应物的功能研究已成为植物和病原细菌互作研究领域的热点，申请人前期工作发现Xoc III型效应蛋白基因XopN与致病相关，该基因在黄单胞菌中非常保守，它可能通过抑制寄主植物先天免疫系统而使植物感病，本课题拟采用分子生物学和功能基因组学等研究技术鉴定效应蛋白XopN的植物靶标基因并对获得的候选靶标基因进行深入研究，阐明XopN及其寄主植物靶标基因作用的分子机理，研究结果将加深我们对Xoc致病的分子机理的理解，有助于发掘可用于抗病育种的功能基因，并为设计高效新型的防治BLS策略提供理论依据。

水稻条斑病（Bacterial leaf streak，BLS)是我国南方水稻生产中最严重的细菌性病害之一，病原为稻黄单胞菌栖稻致病变种（Xanthomonas oryzae pv.oryzicola，Xoc），由于对Xoc致病机理知之不多至今仍未能有效防控该病害。近年来植物病原细菌III型效应物的功能研究已成为植物和病原细菌互作研究领域的热点，申请人前期工作发现Xoc III型效应蛋白基因XopN与致病相关，该基因在黄单胞菌中非常保守，它可能通过抑制寄主植物先天免疫系统而使植物感病，本课题采用分子生物学和功能基因组学等研究技术鉴定效应蛋白XopN的植物靶标基因RACK1B并对其进行深入研究，阐明了XopN及其寄主植物靶标基因作用的分子机理：XopN是通过与RACK1 B的互作，干扰水稻MAPK途径的信号传递，从而影响了水稻中受MAPK途径调控的免疫相关基因的表达、胼胝质沉积等免疫反应。研究结果将加深我们对Xoc致病的分子机理的理解，有助于发掘可用于抗病育种的功能基因，并为设计高效新型的防治BLS策略提供理论依据。